{"id":"a3e37bb6-1a01-53ff-aacb-54375120a124","stable_key":"0f17db03-207f-5910-ac8e-13dfc2f378ce:mg-mouse-tpk-nonmonotonic","predicate":"modulates","statement":"Recombinant mouse TPK1 showed an Mg optimum followed by inhibition as Mg was increased at fixed ATP.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"691c6398-0b16-5633-922c-30f986ed534c","mechanism_event_label":"More magnesium did not continuously increase B1 activation in this assay.","subject":{"id":"bff427ab-35f9-59c2-bb24-fd5953bbaec2","slug":"magnesium-ion","display_name":"Mg2+","entity_type_key":"ion"},"object":{"id":"692f8f7a-32ba-58ff-9242-0784d97f9bff","slug":"mouse-tpk1","display_name":"Mouse thiamine pyrophosphokinase 1","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"691c6398-0b16-5633-922c-30f986ed534c","stable_key":"0f17db03-207f-5910-ac8e-13dfc2f378ce:mg-mouse-tpk-nonmonotonic-event","event_type":"biochemical_relationship","label":"More magnesium did not continuously increase B1 activation in this assay.","description":"Recombinant mouse TPK1 showed an Mg optimum followed by inhibition as Mg was increased at fixed ATP.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"58b974f1-d389-5bf6-81cd-889c44442c42","slug":"atp","display_name":"ATP","entity_type_key":"small_molecule"},"role":"Mg-binding substrate","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"24904faf-f4b4-5e5a-a2e6-3549fb7a2a2e","slug":"mg-atp","display_name":"Magnesium-ATP complex","entity_type_key":"chemical_species"},"role":"complexed substrate","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"36b7c3eb-068b-500f-af1c-078829df1ecc","slug":"thiamine","display_name":"Thiamine (vitamin B1)","entity_type_key":"small_molecule"},"role":"substrate","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"bff427ab-35f9-59c2-bb24-fd5953bbaec2","slug":"magnesium-ion","display_name":"Mg2+","entity_type_key":"ion"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"692f8f7a-32ba-58ff-9242-0784d97f9bff","slug":"mouse-tpk1","display_name":"Mouse thiamine pyrophosphokinase 1","entity_type_key":"protein"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"Magnesium availability supports vitamin B1 activation or cofactor use in the specified preparation; this does not establish a dietary threshold or universal treatment failure.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Purified recombinant mouse TPK1; forward and reverse reaction kinetics.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"ATP concentration shifted the optimum; in vitro values are not intake targets.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Magnesium research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"magnesium","display_name":"Magnesium","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Mus musculus","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"More magnesium did not continuously increase B1 activation in this assay.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[sambon-2022-tpk1] Product inhibition of mammalian thiamine pyrophosphokinase is an important mechanism for maintaining thiamine diphosphate homeostasis (2022). https://doi.org/10.1016/j.bbagen.2021.130071 DOI: 10.1016/j.bbagen.2021.130071","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Purified recombinant enzyme","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"b53b3c63-309c-5338-871c-19038ed10867","evidence_kind":"source_excerpt","locator":"Lines 517-527","start_line":517,"end_line":527,"excerpt":"### mg-mouse-tpk-nonmonotonic\nRecombinant mouse TPK1 showed an Mg optimum followed by inhibition as Mg was increased at fixed ATP.\nCondition category: normal\nnutrient_topic: Magnesium research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: More magnesium did not continuously increase B1 activation in this assay.\norganism: Mus musculus\ntissue_or_cell_type: Purified recombinant enzyme\nexperimental_model: Purified recombinant mouse TPK1; forward and reverse reaction kinetics.\nlimitations: ATP concentration shifted the optimum; in vitro values are not intake targets.\ncross_nutrient: Magnesium availability supports vitamin B1 activation or cofactor use in the specified preparation; this does not establish a dietary threshold or universal treatment failure.\n[sambon-2022-tpk1] Product inhibition of mammalian thiamine pyrophosphokinase is an important mechanism for maintaining thiamine diphosphate homeostasis (2022). https://doi.org/10.1016/j.bbagen.2021.130071 DOI: 10.1016/j.bbagen.2021.130071","model_system":"Purified recombinant mouse TPK1; forward and reverse reaction kinetics.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [sambon-2022-tpk1] Product inhibition of mammalian thiamine pyrophosphokinase is an important mechanism for maintaining thiamine diphosphate homeostasis (2022). https://doi.org/10.1016/j.bbagen.2021.130071 DOI: 10.1016/j.bbagen.2021.130071","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"dd101e28-1a2e-5a48-9d1e-809c77514866","stable_key":"import-0f17db03-207f-5910-ac8e-13dfc2f378ce","title":"Magnesium: cross-nutrient mechanisms and deficiency (2026-09-17)","document_type":"imported_text","citation_label":"AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text.","file_path":"","sha256":"e111c412f57143a17e8e65e74e8f7888b5bb9a61099873f4767f527fac19bb07","revision_id":"6b7f04f2-66ed-5859-955f-c2b50d4bf041","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}